Process for producing (2R, 3S) -3-amino-1, 2-oxirane

A process for producing (2R,3S)-3-amino-4-phenylbutane-1,2-epoxide compounds represented by the general formula (8):

• 6
• wherein R1 represents an amino-protecting group,
• which comprises
• treating a (2S,3S)-3-amino-1-halo-2-hydroxy-4-phenylbutane compound represented by the general formula (1) or a (2S,3S)-3-amino-4-phenylbutane-1,2-epoxide represented by the general formula (2):
• 7
• wherein R1 is as defined above and X represents a halogen atom, 8
• wherein R1 is as defined above,
• with a carboxylic acid quaternary ammonium salt represented by the general formula (3) or a carboxylic acid metal salt represented by the general formula (4):
• R3R4R5R6N+OCOR2− (3)
• wherein R2 represents an alkyl, aryl or aralkyl group and R3, R4, R5 and R6 may be the same or different and each independently represents an alkyl or aralkyl group,
• R2COO−M+ (4)
• wherein R2 is as defined above and M represents a metal atom, and a quaternary ammonium salt represented by the general formula (5):
• R3R4R5R6N+Y− (5)
• wherein R3, R4, R5 and R6 are as defined above and Y represents a halogen atom, to give a (2S,3S)-1-acyloxy-3-amino-2-hydroxy-4-phenylbutane compound represented by the general formula (6):
• 9
• wherein R1 and R2 are as defined above,
• further treating said (2S,3S)-1-acyloxy-3-amino-2-hydroxy-4-phenylbutane compound with a sulfonic acid halide in the presence of an organic base, to give a (2S,3S)-1-acyloxy-3-amino-2-sulfonyloxy-4-phenylbutane compound represented by the general formula (7):
• 10
• wherein R1 and R2 are as defined above and R7 represents an alkyl, aryl or aralkyl group,
• furthermore treating said (2S,3S)-1-acyloxy-3-amino-2-sulfonyloxy-4-phenylbutane compound with an inorganic base.